If you google around, you'll find oodles of info. I think there are also a few posts here you can search out on it.

I read up on it a little while ago and basically came to the conclusion that it is a). a painstaking process that I don't currently have the tools for and b). actually no less costly since for larger tanks tempered glass is required.

Unless you own and work in a glass cutting facility and have a wide variety of tools that will be needed for the job...it's almost never worth making a tank. Small tanks are just too cheap to purchase (you should be able to find a brand new 55 gallon tank for under $100) to make the hassle cost effective. Large tanks take a lot of care (and thick, expensive glass) because of the pressure that much water will put on it.

An exception might be to make an incredibly large tank that doesn't need to be a "show tank" out of plywood. These can be made with a single panel of glass for viewing. I wouldn't bother with this hassle unless the tank was going to be several hundred gallons, myself...and finding a place to put a monster like that is another problem._________________

Just to add another point to this...My wife and I own and operate a picture framing business...same location for 14 years. We cut square, oval, circle, octagon and lots of other odd shaped glass. I am excellent at cutting glass to fit and I obviously purchase glass at wholesale. Yet, I won't even consider making my own tanks. The standard sized tanks are priced so low that the savings even I could receive aren't worth the trouble and risk of building my own. The only exceptions would be as Cy already alluded to, the large plywood tanks, or a custom sized tank. Custom size tanks are very expensive and warrant a more serious look at DIY projects...if you have the expertise to accomplish the tasks. Glazing isn't as simple as it looks._________________

ever try plexi-glass, it works and its a little cheaper than glass, and it can be chemically welded, the sea;ants r not very expensive but uou do need to have enought working space, clamps, router, and some fine cut saw bladesif ya have any questions just ask me.

Mobern, Most (not all) tropical keepers on this board have 10 - 30 - 75 Gal. tanks. At these volumes it IS cheaper to buy a tank than build one. Check out a cichlid specific board or a catfish board and see the difference in attitudes though. Those keepers need big tanks so they often sucessfully D.I.Y.

In the olden days D.I.Y. tanks of plywood were very common as fish keeping was exotic and expensive. It was really uncommon to find 300 Gal. tanks ready made. The process is not that impossible if you really think things out first and "really enjoy" the satisfaction of D.I.Y.

(now... I sit back and wait for the whipping )_________________Think like a fish

Nah, no whipping from me.
In fact, I'm gearing up to start making monster plywood tanks for a living, among other custom carpentry.

I wouldn't try to make any tank under 150 gallons; it's just not worth it. The epoxy paint alone costs some 60 bucks a gallon, so it's not worth buying for making small tanks. It might be fun to make finely ornate and artistic tanks in small sizes, I suppose, but it wouldn't be profitable unless I could find a market for such tanks among those with more dollars than sense.